The present invention relates to a diving face mask a diver puts on his or her face during diving such as skindiving or scuba-diving and more particularly to such a diving face mask allowing a lens exchange to be easily achieved.
FIG. 8 in the accompanying drawings is a perspective front view showing a diving face mask 100 of prior art as partially exploded. The mask 100 comprises a pair of transversely opposite front lenses 2, a main frame 103 having a front section to which the lenses 2 are detachably attached and a rear section adapted to be tightly put over a wearer's face, and a strap 4 attached to the main frame 103 so as to be releasably fastened around the wearer's head. The main frame 103 comprises a lens frame 105 of hard plastic and a skirt 6 of soft rubber. The lens frame 105 comprises an outer peripheral frame 8 having a pair of transversely opposite lens holding portions 7, a pair of inner peripheral frames 109 (referred to also as lens frames) adapted to bear against the front surfaces of the lenses 2 snapped in the holding portions 7 and a frame holding member 110 detachably mounted on a central part of the outer peripheral frame 8.
Each inner peripheral frame 109 is an annular member of substantially same contours as the holding portion 7 and has at desired locations along its outer periphery a convex engaging portion 131 adapted to be engaged with a concave engaging portion 19 provided in the inner peripheral surface of the holding portion 7 and a knob section 101 extending towards a central front surface of the outer peripheral frame 8.
With this mask 100 of prior art, the convex portion 131 snaps into the concave portion 19, on one hand, and a rear surface of the inner peripheral frame 109 bears against the front surface of the lens 2, on the other hand, as the inner peripheral frame 109 is fixed into the holding portion 7 after the lens 2 has been fixed thereinto, so that the lens 2 is prevented from slipping off from the holding portion 7. Then the frame holding member 110 covers the knob section 101 of the inner peripheral frame 109 as the frame holding member 110 is mounted on the outer peripheral frame 8 and, in consequence, the member 110 functions to protect the knob section 101 against being exposed to foreign substances. To perform a desired operation of lens exchange for the mask 100 assembled in this manner, the frame holding member 110 is removed, then a blade of a screw driver is inserted between the inner peripheral frame 109 and the outer peripheral frame 8, the inner peripheral frame 109 is yielded inwards radially of the frame 109 by the blade so that the convex portion 131 and the concave portion 19 are disengaged from each other and the inner peripheral frame 109 is pulled with the knob section 101 by hand.
To disengage the inner peripheral frame from the mask of prior art as has been mentioned above, not only an operating tool such as the screw driver but also a skill of a wearer is required. So it is difficult for an unskilled wearer to exchange a lens.
In view of the above-mentioned problem, it is a principal object of the invention to solve the above-mentioned problem by cutting away the inner peripheral frame partially in its circumferential direction so that the frame can be deformed inwards radially thereof.